Sound signal



March 17, 1931.

R. M. CRITCHFIELD SOUND S I GNAL Filed may 2s. 192% Patented Mar. 17,1933.

entran s'rArEs PATE-Nr? eri-ICE ROBERT M. CRITCHEIELD', 0E ANDERSON,INDIANA, AssIeNoR 'ro' DELCo-RENY conroRATIoN, or ANDERSON, INDIANA, ACORPORATION or DELAWARE SOUND SIGNAL Application ined- May as,

This invention relates to sound signals and is particularly adapted tothat class of signals operated by fluid pressure means.k

The main object of this invention is the production of a novelsignalling device adaptable for use on automobiles and the like andcapable of producing a comparatively loud signal that will carry 'longdistance, and one that isV of a musical tone or In combination ofmusical tones, preferably of a harmonious character.

It is an object of kthis invention to provide' a sound signal of theclass described, which will be eicient in its operation and I5 willproduce a pleasingwar'ning signal, and

will bev attractive in appearance.

It is a further object of this invention to provide a sound signal oftheclass described which is capable of mass production at a re- 20 ducedcost.

It is a further object of the invention to provide a structure in whichthe relation between the reflector and tone elementmay be varied so asto produce the most efficient operation or the most desired warningsignal, and so as to accomplishl the niceties of tone inflectionresidual in a sound signal of this type.

Further objects and advantages of the present invention will be apparentfromv the following description, reference being had to the accompanyingdrawings, wherein a preferred-embodiment of one form of the presentinvention is clearly shown.

In the drawings: Fig. 1 is a longitudinal section through the improvedsound signal.

Fig. 2 isa cross section through the windway and intake passagesubstantially as indicated bythe line and arrows 2 2 of Fig. 1.

Fig. 3 is a sectional view through the foot 0f the sound producingelement, disclosing the cross sectional relation of the windway tube andlanguette block, substantially as indicated by the line and arrowsy 3 3of Fig. l.

Figs. 4 and 5 are cross sections through the pipes or tone elements,substantially as indicated by the lines and` arrows 1 4 and 5 5respectively of Fig. 1.

1929. seriai No. accesa.

With .particular reference to the drawings', 2() refers to a reflector,preferably of a'I carabolic form, which is supported at the apen thereofby a bracket 2l, by which it may be secured to an automotive vehicle.The re'- flector 20 is flanged at 22 to establish ri"- gidity of thereflector and to lower the fundamental tone thereof. At thev a'Xi's ofthe re'- flector and bracket, a tubular member 23 is secured bycomplementarily threadedV pertions, in axial apertures of the bracketand reflector, and the member 23, the threaded portion of the member 23'being relatively long so as' to provide considerable adjustment of themember 23 in and out of the bracket and reflector. It willV be notedfrom the illustration that the member 23i's threaded from the inner endor the end disposed withinth'e reector for a' substantial distancelthroughout its length andn that it supports` exterior of the bracket 21a'lock nut 24, which functions to secure the member 23v and' reflectorin the adjusted position. j l Y The member 23 in? itselfl provides awindway 25 and while it is substantially cylindrical throughoutthe'threaded portion thereof the portion exterior of the bracket 21maybe angular or polygonall in outside contour, as indicated at 26, so thata wrench orI other instrument may be applied thereto for turningrelative to the bracket 21. `The eXtreme rear end 27 is threaded andprovided with a special cap 28 disposed against a gasket 29 which closesthis end ofthe member against air leakage. The tubular memberis'provided with the cylindrical bore which defines the windway 25, andprovides a' receptacle for a block 30 integrally joined with the capmeniber 28 by a vsleeved extensionor stem of the block. 4 f

The block 30 is substantially cylindrical in formation at the forewardpart thereof, and of slightly less'cros's sectional' diameter than thebore of the windway 25, so as to provide an annular passage between itand' theinner wall of the member 23, as illustrated at 31'yin Figs. 1and 3. This annular passage isknown as a flue, and in the presentinstance is substantially apportioned in three parts by means of thespacing' lugs 323 positined at` points about the block 30 as illustratedin Fig. 3. These spacing lugs 32 are of such dimension as to be firmlyreceived within the bore of the windway, and to maintain the block inpredetermined spaced relation with respect to the member 23.

'Ihe dimensions of the cap 28 and the windvvay member 23 and the block30 are such that, kwhen these parts are assembled by threading themember 23 through the member 28 as shown, the right angular spaces ofthe block 30 will be iush with or in planar alignment with the extremityor lip 34 of the member 23, the block 30 thus forms a languette whichcooperates with the tone pipes to be described. The windway 25 hasprovision for connection with a source of fluid pressure by means of athreaded nipple 35 which may be secured thereto in any convenientmanner, or position as indicated in Figs. 1 and 2.

In the present instance the cap 28 and block 30 support centrallythereof` a stud 36 threaded at each end as at 37 and 38. The threadedend 37 is provided with a nut 39 which is disposed against the outsideof the cap 28, and the end 38 is threaded into the partition wall 40 ofthe tone producing element, a spacer 41 being disposed between the endof the partition and the languette or block 30. When the stud 36 hasbeen assembled with the stated elements, the nut 39 is run up to clampthe parts tightly together, and in order to rigidly support the pipes.

The tone producing element is substantially of tubular formation, and inthe present instance comprises a cylinder 42 with a portion thereof cutaway as at 43. rIhe partition member 40 is disposed substantiallydiametric thereof and extends throughout the entire length thereof asillustrated in Fig. 1. The partition member 40 is secured in placewithin the cylinder 42 by means of solder 0r other preferred means, anddivides the cylinder 42 into a pair of substantially semi-cylindricalpipes 44 and 45. The remote ends of these pipes are closed by members 46and 47 respectively, as illustrated in Fig. 1 and the pipes differ inlength, an equivalent'to the cut away portion 43. The forward end ofeach pipe terminates in a squared end, and situated in substantially thesame plane which is practicallyv parallel to the plane of the languette33 and lip The terminating edge of the cylinder 42 is chambered orbevelled to provide two semicylindrical lips 48 and 49 on the open endof the pipe adjacent the languette 33 and iue 3l with which it isdesigned to cooperate. By reference to Fig. 1 it will be noted that whenthe elements are assembled in the relation stated, that the tone elementor pipes and the Windway assembly supporting the tone element, are inliXed spaced relation "f end to end and so that the lips 48 and 49 areincase? disposed in operative alignment With the flue 3l by means of theinterposed spacer 41. This structure provides an embouchure of annularform about the spacer 41, and betwen the lips 48 and 49 of the pipes andthe lip 34 surrounding the languette 33. On the other hand, it may besaid that the embouchure is arc like or substantially semi-cylindrical,when speaking with reference to the pipes 44 and 45 by themselves.

While I have illustrated the device with a singleV spacer 41 disposedbetween the tone element and the windway, I do not propose that thisshowing determines the eXact dimension or relative size of the spacerwith respect to the elements with which it is assembled. In practice Ifind it preferable to provide a plurality of spacers 41 varying inthickness so that the relation between the lips of the pipe and thelanguette'may be varied by using one or another of the spacers, or byusing them in various combinations as may be desired. In other words,the magnitude of the embouchure may be varied as conditions may require,or notions of the operator may deem advisable. Further, by the longthreaded portion 23 of the wind- Way means are provided for altering therelation of the embouchure of the pipes relative to the focal point ofthe reector 20, it being clear that this may be accomplished byloosening the lock nut 24, and rotating the reflector relative to thewindway tube until the desired result is obtained, and then resettingthe lock nut 24 to maintainl the parts in predetermined relation. l

In the operation of this sound signaliluid under pressure is admitted tothe windway 25 by way of the nipple 35, and from thence the fluid eXitsunder pressure through the flues 31 across the embouchure where itstrikes the lips 46 and 47 setting the pipes 44 and 45 into vibration.The tones produced will be determined in main by the length of the pipes44 and 45 and the magnitude of the embouchure across which the fluidcurrents How and eddy against the languette 33. The sound thus producedbeing substantially at or near the focal Vpoint of the refiector will bepicked up by the reiiector and be reflected substantially along the axisthereof, so that the sound producedf may be heard at some distance infront of the signal device. I

While the form of embodiment of the present invention as hereindisclosed. consti.- tutes a preferred form, it is to be understood thatvother forms might be adopted, all coming within the scope of the claimswhich follow.

What is claimed is as follows:

1. In a sound signal the combination cornprising, a reflector, a bracketsupporting said reliector and a fluid pressure tone element coaxial ofsaid retlectorand supported by said bracket, said tone elementcomprising a pair of .semi-cylindrical closed pipes, a cylindricalwindway enclosing a cylindrical languette and means securing said pipesand languette in spaced relation.

2. In a sound signal the combination comprising, a reflector, a bracketfor said reflector, a cylindrical Windway central of said bracket andreflector, a cylindrical languette Within said windway and supporting apair of closed pipes, said languette and pipes defining a sound sourcesubstantially at the focal point of said reflector.

3. In a sound signal the combination cornprising, a reflector, a bracketsupporting said reflector, a tubular windway adjustably secured in thebracket at the axis of said reflector, and a pair of pipes secured inoperative relation with said windvvay and disposed along the aXis ofsaid reflector, said windvvay providing flues for cooperation with thelip of each pipe.

et. In a sound signal the combination comprising, a reflector, a bracketsupporting said reflector, a windway coaxial of said reflector andsecured to said bracket, means closing one end of said windway andproviding a languette near the focal point of said reflector, a pair ofpipes secured to said languette so as to present their lips in operativerelation with the flue defined by said languette and windway, saidwin-dway and bracket being relatively movable so as to vary the positionof the sound source relative to the focal point of said reflector.

5. In a sound signal the combination comprising, a reflector, a bracketsupporting said reflector, a tubular windvvay adjustably secured in thebracket at the aXis of said reflector, a cap for closing one end of saidwindway and integrally connected with a block within said windway, saidblock formed to provide a languette adjacent the other end of saidWindway and arranged substantially at the focus of said reflector, aplurality of pipes secured to said languette to present their lips incooperative relation with the flue defined by said languette andwindway.,

6. In a sound signal having a reflector, a bracket supporting saidreflector and a fluid pressure tone element, the combination comprising,a tubular windway secured axially of sai-d reflector, a can closing oneend of said windway and providing a cylindrical block within and at theother end of said windway, said block being of similar shape and of butlittle less in cross sectional area than the cross section of saidwindway, the periphery of said block being provided with spacing lugs tomaintain predetermined spaced relation between said block and the wallof said windway, and to define arc like flues, a stud provided by .saidblock and supporting a plurali'ty of pipes in conjunctive relation withsaid llues, said pipes being closed at one end -)ressure tone elementthe combination coinprising a cylindrical windway adjustably secured tothe bracket and lying along the axis of the reflector, means closing oneend of said windway, and -a languette within said windway substantiallyclosing the other end thereof, said languette supporting a plurality ofopen ended pipes and arranged in close uxtaposition to the walls of saidwindway to vprovide flues for said pipes, and one end of said pipesbeing lipped and positioned for cooperation with said flues.

8. In a sound signal having a reflector, a bracket supporting saidreflector and a fluid pressure tone element, the combination comprising,a cylindrical windway adjustably secured to said bracket and providingone end thereof near the focal point of said reflector, means closingthe rear end of said windway and providing a languette at the other endthereof, said languette lying within said 7indway and providing arc likeflucs therebetween, a cylindrical pipe provided with a partitiondividing the pipe into chambers of various dimensions, a stud threadedinto said partition and securing said pipes to said languette, and aspacer disposed between said languette and pipes.

9. In a sound signal having a reflector, a bracket supporting saidreflector and a fluid pressure tone element, the combination comprising,a tubular windway secured at the aXis of said reflector and providing alanguette substantially at or near the focal point of said reflector, apair of pipes secured to said languette and a spacer disposed betweensaid pipes and languette to provide an annular embouchure between thelip of said pipe and the flue defined by said cylindrical windway andlanguette.

10. A sound signal having a reflector, a bracket supporting saidreflector and a fluid pressure tone element, said tone elementcomprising a pair of pipes of semi-cylindrical fcrmation providing tonechambers of different length, a common wall between said pipes, a studsecured to said common wall and providing a support for said pipe, awindway provided at the axis of said reflector and supporting saidpipes, and means for altering the relation of said reflector andwindway, so as to predetermine the position of said tone element withrespect to said reflector.

l1. In a fluid pressure sounding signal, the combination of a windway, atone element supported thereby, and a reflector therefor, with means foraltering the relation of said reflector and tone element.

412. The combination set forthin yclaim ll which the Windway .comprisesa tubular member supported axially off said reflector :and providing a'languette to Which is secured a pair of pipes.

13. The combinati-ion set forth in claim 11V in which the WindW'aycomprises a tubular member supported axially of said reflector andproviding a languette to Which is secured a pair of pipes, a Ispewingmember disposed .between said languette and pipes for ldeinermirliiigthe embouchure between the lip of said pipe and the flue between the1anyguette and Windway.

In testimony Whereolkl I hereto affix signature.

ROBERT M. CRITGHFIELD.

